A flow rate adjusting device including a flow rate adjusting portion that adjusts the flow rate of a liquid, such as a drug solution or pure water, which is used for semiconductor manufacturing devices has been conventionally known (for example, see Japanese Unexamined Patent Application, Publication No. 2004-162774 (hereinafter referred to as “JP 2004-162774”)).
The flow rate adjusting device disclosed in JP 2004-162774 has a structure in which a compression chamber is pressurized to depress a diaphragm so as to allow a valve body to be spaced apart from a valve seat, thereby causing a fluid to flow from an upstream-side first space into a downstream-side second space. The second space communicates with an exit port, so that the fluid flowing into the second space flows to the outside of the device from the exit port.